1. Field of the Invention
The present invention relates to an emergency call system with a battery switching function in which various functions such as protection of vehicle-members, prevention of the occurrence of vehicle-theft and a function for informing a legal user or a prescribed administrative agency of a present state of a vehicle when the vehicle is stolen are correctly operated in severe circumstances.
2. Description of Related Art
For example, to protect members of a vehicle when an accident of the vehicle happens, a member protecting apparatus, in which air bags are operated according to the detection of the vehicle accident, is known as a prior art. Also, to prevent the occurrence of vehicle-theft when an illegal user tries to start the operation of an engine by inserting a key into a vehicle, a vehicle-theft preventing apparatus is known as another prior art. In this vehicle-theft preventing apparatus, a password of a legal key registered in advance is compared with that of the key possessed by the illegal user. In cases where a comparison result indicates that the operation of the engine is started by using an illegal key, it is judged that the vehicle is about to be stolen. Therefore, an alarm is rang by the operation of the vehicle-theft preventing apparatus, or the operation of the engine is automatically stopped by the operation of the vehicle-theft preventing apparatus while turning a lamp on and off.
The member protecting apparatus and/or the vehicle-theft preventing apparatus are arranged in the vehicle and are operated by receiving a prescribed voltage of an electric power supplied from a battery. This battery is arranged in the vehicle to apply the prescribed voltage to the member protecting apparatus and the vehicle-theft preventing apparatus, and the apparatuses are stably operated.
However, in cases where the prescribed voltage of the battery, which is put in severe circumstances is lowered to a value lower than a pre-set voltage, there is a problem that each of the member protecting apparatus and the vehicle-theft preventing apparatus cannot be correctly operated.
Also, in cases where an electric power supply line, which is required to operate the member protecting apparatus in vehicle collision, is cut off, there is another problem that each air bag is not correctly operated.